Which fo the following stereosimers represent meso compounds?

Options

A.
B.
C.
D. All of these

Answer

D

Explanation

In `(1)` and `(2)`, a plane of symmetry cuts through the central carbon and the two horizontal ligands revealing that the top half of the molecule is the mirror image of the bottom half. It does not matter which ligands ate bonded to this carbon because they are within the symmetry plane. This is also true in `(3)` if `n =1` or an odd number. However, if `n` is an even number, the symmetry plane cuts through the central `C-C` bond.